Today's Message Index:
----------------------
1. 03:44 AM - Re: Re: Starter Contactor location on a Long-EZ (Michael Garmon)
2. 07:17 AM - Ground protection (Richard Girard)
3. 07:58 AM - Re: Starter Contactor location on a Long-EZ (Airdog77)
4. 08:32 AM - Re: Re: Starter Contactor location on a Long-EZ (Dj Merrill)
5. 11:24 AM - Re: Re: Starter Contactor location on a Long-EZ (don van santen)
6. 01:05 PM - Re: Starter Contactor location on a Long-EZ (Airdog77)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Starter Contactor location on a Long-EZ |
Bob,
There is an account of the incident on Brian Deford=99s website locate
d at http://deford.com/cozy/fire.html.
I am also considering installing the starter solenoid on the inside (cabin s
ide) of the firewall. I also plan on protecting alternator B leads with fusi
ble links sized to protect the wire ( larger than the alternator capacity). I
n this way, any wire crossing the firewall will be protected.
Michael Garmon
Cozy Mk IV
Houston, TX
Sent from my iPad
> On Jan 26, 2018, at 6:56 PM, Robert L. Nuckolls, III <nuckolls.bob@aeroele
ctric.com> wrote:
>
> At 05:08 PM 1/26/2018, you wrote:
>>
>> Bob,
>>
>> Roger... I'll go back and take a deeper look at all this.
>
> Is there a published failure analysis of
> what transpired in the unhappy event?
>
> A significant proportion of my career in aviation
> focused on what-went-wrong-and-why. In hind-sight,
> I wish I had kept a journal on the various inquiries,
> facts found and resolution of root causes. I
> can state with confidence that a majority of
> failure events had root cause in 'somebody
> didn't read/understand some bit of history in
> design or application.
>
> A few instances, like the sticking trim relays on the
> Beechjet, involved new discoveries. But most unhappy
> events were founded on inattention to rudimentary
> details. I've worked some exceedingly expensive
> problems ($millions$) that had roots in $100
> decisions . . .
>
> Whatever you decide to do with your airplane,
> it NEVER hurts to take some pictures, post to
> the List and ask questions. The most elegant
> solutions are invariably a team effort by
> competent observers. You'll have a hard time
> finding a more capable group than right here . . .
>
> Bob . . .
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Ground protection |
After watching a friends bike go up in flames from a short I did some
thinking about the situation. I decided that I wanted some protection from
a similar fate and came up with a solution. I put a 50 amp switch in the
ground line from the battery to the frame. The logic was that with this
arrangement I could kill any short circuit by throwing a single switch
rather than having to find the offending wire. Located in a covered
location it was also cheap theft insurance. I just switched it off when I
parked. In 20 years I had one switch failure, most likely a victim of the
"Vibraglide's" rigid engine mounting setting the whole bike into spasms. On
the road it was a momentary annoyance to remove the seat, take the switch
out of the line and motor on to the auto parts store. Airborne it probably
wouldn't be as easy.
It seems to have been a valid solution for the Harley but is it good
practice otherwise?
Rick Girard
--
=9CBlessed are the cracked, for they shall let in the light.=9D
Groucho Marx
<http://www.goodreads.com/author/show/43244.Groucho_Marx>
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&ut
m_campaign=sig-email&utm_content=webmail>
Virus-free.
www.avg.com
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&ut
m_campaign=sig-email&utm_content=webmail>
<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Starter Contactor location on a Long-EZ |
Bob,
I have to admit I'm puzzled on what appears to be sticking to the standard convention
of mounting the starter contactor/solenoid on the firewall of a pusher
aircraft when the A-to-Z of the power distribution configuration is different
than a traditional tractor airplane.
If we look at the different configurations, which I spelled out in asking advice
on this from some canard builder/fliers, it looks like this:
1. Tractor: FIREWALL >> Battery >> Battery Contactor >> shorter big wire >> Starter
Contactor >> Starter
2. "Standard" Pusher: Battery >> Battery Contactor >> longer big wire >> FIREWALL
>> Starter Contactor >> Starter
3. "New" Cozy style: Battery >> Battery Contactor >> longer big wire >> Starter
Contactor >> FIREWALL >> Starter
Not to be critical of Brian in any way, and in the discussion I discovered in support
of placing the starter solenoid on the cold side of the firewall, was a
point made that he "didn't turn off the master" which controls the power flow
through the big power cable, as is a prominent feature of #2 above. I understand
doing analysis on past events, and looking at standard practices in an attempt
to mitigate potential issues (which is exactly what I'm attempting here),
but Brian's scenario isn't the only reported instance of smoking wires in a
pusher, it's simply the most tragic (that I know of).
The second point in this discussion is that if control of the electron flow through
the big cable ends at the cold side of the firewall (as is proposed), and
the only (initial) action that results in electrons flowing across the firewall
boundary is when the starter button is depressed... then very most likely only
one action is required if there is any malcontent going on "back there" and
that is simply to STOP pressing the starter button. Then Step 2: TURN OFF THE
MASTER is moved from the critical column to the probably a good idea column.
Moreover, the ancillary logistical benefits of moving the starter contactor to
the cold/forward side of the firewall in routing wires is quite significant.
It simply makes for running less wires through the firewall, wire runs to the
Hall Effect sensor for both the primary and SD-8 backup alternators are optimized,
and it places more items in the rather empty Hell Hole area and gets them
off a very crowded firewall. In short, it just really appears on the face of
it to make for an easier install and a safer operational setup.
And again, going back to my original statement, I'm not really sure why the starter
contactor/solenoid should be on the hot side of the firewall in a pusher
airplane. Moreover, in looking at the pros/cons for moving the starter solenoid
to the cold side, the pros vastly outweigh any cons that I could find. Not
that I am in any way the most knowledgeable on this stuff, but from what I know,
have researched and discussed it appears to be the best option thus far.
Regards,
Wade
--------
Airdog
Wade Parton
Building Long-EZ N916WP
www.longezpush.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=477632#477632
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Starter Contactor location on a Long-EZ |
On 1/27/2018 10:57 AM, Airdog77 wrote:
> 2. "Standard" Pusher: Battery >> Battery Contactor >> longer big wire >> FIREWALL
>> Starter Contactor >> Starter
>
> 3. "New" Cozy style: Battery >> Battery Contactor >> longer big wire >> Starter
Contactor >> FIREWALL >> Starter
Hi Wade,
FWIW, with my battery in the tail, the system in my tractor config
Glastar is the same as #2.
I don't see any immediate reason why #3 should not work.
In either case, the protections of the big wire going through the
firewall should be the same.
I also agree with the other folks that if the installation is done
properly, #2 should also be fine. My Glastar has been flying with this
configuration for 18 years, and other aircraft far longer. From an
electrical perspective, I do not see any differences between a pusher
versus a tractor.
It is your airplane, and you need to do what will make you feel
comfortable, IMHO.
-Dj
--
Dj Merrill - N1JOV - EAA Chapter 87
Currently Flying: Glastar
Previously: Cessna 150 - Glasair 1 FT - Grumman AA1B
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Starter Contactor location on a Long-EZ |
Wade, are you forgetting the two alternator "b" leads? In the contactor on
the cold side they both have to pass through the firewall. In the std setup
they connect to the hot side of the starter contactor.
Don
On Saturday, January 27, 2018, Airdog77 <Airdog77@gmail.com> wrote:
>
> Bob,
>
> I have to admit I'm puzzled on what appears to be sticking to the
standard convention of mounting the starter contactor/solenoid on the
firewall of a pusher aircraft when the A-to-Z of the power distribution
configuration is different than a traditional tractor airplane.
>
> If we look at the different configurations, which I spelled out in asking
advice on this from some canard builder/fliers, it looks like this:
>
> 1. Tractor: FIREWALL >> Battery >> Battery Contactor >> shorter big
wire >> Starter Contactor >> Starter
>
> 2. "Standard" Pusher: Battery >> Battery Contactor >> longer big wire
>> FIREWALL >> Starter Contactor >> Starter
>
> 3. "New" Cozy style: Battery >> Battery Contactor >> longer big wire >>
Starter Contactor >> FIREWALL >> Starter
>
> Not to be critical of Brian in any way, and in the discussion I
discovered in support of placing the starter solenoid on the cold side of
the firewall, was a point made that he "didn't turn off the master" which
controls the power flow through the big power cable, as is a prominent
feature of #2 above. I understand doing analysis on past events, and
looking at standard practices in an attempt to mitigate potential issues
(which is exactly what I'm attempting here), but Brian's scenario isn't the
only reported instance of smoking wires in a pusher, it's simply the most
tragic (that I know of).
>
> The second point in this discussion is that if control of the electron
flow through the big cable ends at the cold side of the firewall (as is
proposed), and the only (initial) action that results in electrons flowing
across the firewall boundary is when the starter button is depressed...
then very most likely only one action is required if there is any
malcontent going on "back there" and that is simply to STOP pressing the
starter button. Then Step 2: TURN OFF THE MASTER is moved from the
critical column to the probably a good idea column.
>
> Moreover, the ancillary logistical benefits of moving the starter
contactor to the cold/forward side of the firewall in routing wires is
quite significant. It simply makes for running less wires through the
firewall, wire runs to the Hall Effect sensor for both the primary and SD-8
backup alternators are optimized, and it places more items in the rather
empty Hell Hole area and gets them off a very crowded firewall. In short,
it just really appears on the face of it to make for an easier install and
a safer operational setup.
>
> And again, going back to my original statement, I'm not really sure why
the starter contactor/solenoid should be on the hot side of the firewall in
a pusher airplane. Moreover, in looking at the pros/cons for moving the
starter solenoid to the cold side, the pros vastly outweigh any cons that I
could find. Not that I am in any way the most knowledgeable on this stuff,
but from what I know, have researched and discussed it appears to be the
best option thus far.
>
> Regards,
> Wade
>
> --------
> Airdog
> Wade Parton
> Building Long-EZ N916WP
> www.longezpush.com
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=477632#477632
>
>
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Starter Contactor location on a Long-EZ |
Hi Don,
As for big wires coming off the Starter Contactor I have an 8 AWG B lead from the
alternator that connects to the same lug on the hot side of the starter contactor.
On the other side of the starter contactor I have a 6 AWG lead going
to the starter.
Yes, I do have an 18 AWG F-lead that also comes off the alternator that transitions
through the firewall back to the Voltage Regulator, but I was looking primarily
at the heavy gauge wires through the firewall. I understand the 8 AWG
wire traversing the firewall is still on the hot side of the contactor, connected
to the same post as my mega cable coming from the nose, but it is a lot more
manageable.
Thanks,
Wade
--------
Airdog
Wade Parton
Building Long-EZ N916WP
www.longezpush.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=477636#477636
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|